Wrench apparatus for a hypodermic syringe



y 1957 J. c. TASCIOTTI 2,800,816

WRENCH APPARATUS FOR A HYPODERMIGSYRINGE Filed Feb. 28, 1956 V INVENTQR JnMEs 6.771scmrn v ATTORNEY Uniwd Application February 28, 1956, Serial No. 568,294

1 (Claim. (Cl. 81-334) The instant invention relates to a wrench designed to facilitate removal of a needle from a hypodermic syringe without injury to the. person removing same and, in addition, without damage to the needle or other parts of the syringe.

The hypodermic syringe commonly in use consists of a fluid-carrying barrel to which a needle-carrying hub is fastened. The hub of one type of syringe is provided with an inner tapered surface designed for press fit connection to a tapered lower end of the barrel. The other end of the hub is provided with a cylindrical opening to receive and hold fast thereto the shank of the needle. After use, the nurse or doctor removes the hub, the needle remaining fastened thereto, and places these elements in a sterilizer. These elements are replaced by a clean hub and its fastened needle when the syringe is to be used again. Ordinarily there is no problem or unusual efifort required to apply the clean hub to the barrel of the syringe. The connection is easily made by jamming the hub onto the tapered surface of the syringe. Above all, the connection must be absolutely dependable for safe use of the syringe. Accordingly, the tapered surface of both hub and barrel are specially designed and fabricated to provide a connection which will not disengage during use of the hypodermic syringe.

When the doctor or nurse attempts to disengage the hub from the barrel after use of the syringe, it is the experience of the profession that the strong and dependable press fit provided by the tapered connection is very diflicult to disengage. As a matter of fact, and it is common knowledge that, removal of the hub requires a large and strong turning force in attempting to twist it off the syringe. Instances have been reported where the doctor or nurse has suffered injuries as drastic as broken wrists. More frequently, though, the doctor or nurse, in straining to twist off the hub, has either broken the barrel in spite of the fact that it is made of a strong stransparent plastic material, or, upon a sudden and unexpected disengagement during the extreme twisting force being applied. the doctor or nurse has jammed the needle against a desk top or other piece of furniture and caused the needle to be broken, jammed the needle into ones self or sprained a wrist.

The problem of removing the needle-carrying hub is troublesome. Either the barrel or needle is broken in the process or the person removing same injures himself by self-imposed pricks of the needle, or by straining or breaking his wrist. The needle is fragile. Moreover, it offers little, if any, surface to permit one to grip same to exert a large twisting force. In addition to attributing the fastholding tapered fit as a cause of these undesired results, it is also known that the hub and needle and other components of the syringe do not offer the person attempting ts Patent to remove the needle any solid or safe surface to grip the Patented July 30, 1957 affords no accessible surface to allow a solid and strong grip upon disconnection.

It is, therefore, the principal object of the instant invention to provide a wrench which ensures safe and damage-free removal of the hub and its supported needle from the hypodermic syringe.

It is another object of the instant invention to provide an elongate wrench having a socket into which the hub of the needle is nestled. The transverse arms of the wrench provide handles for twisting off the hub from the syringe. The arms also provide the leverage which makes removal of the hub especially easy. A mere twist of the wrench effects separation. The leverage afforded by the oppositely extending arms transverse to the axis of the syringe eliminates the need for an operator to exert large twisting forces.

It is another object of the invention to provide needle passages in the nature of slots and openings along the side and under faces of the wrench and communicating with the socket. The syringe is nestled in the socket by first passing the needle through the passages while the needle and wrench are relatively transposed so that at all times the needle point is held below the wrench and thus shielded against striking the wrench and also to prevent accidental pricking of the person effecting disconnection.

It is another object of the instant invention to provide a wrench of sufficient leverage to eliminate the extreme forces required to effect separation of the hub from the syringe and thus avoid injuries to the person or damage to the syringe that are accidentally caused by sudden disconnections.

It is a further object of the invention to provide a wrench adaptable to accommodate syringes of different sizes. Syringes and the outer hub dimensions thereof vary to accommodate needles of progressive sizes. Furthermore, syringes of comparable sizes, but made by different manufacturers, are often found to have hub dimensions that differ. Rather than propose a wrench for syringes of each particular size, by the use of spring means, a single wrench may accommodate syringes over a range of progressive sizes. In the illustrated embodiment, at spring-pressed ball is mounted in a wall of the socket and protrudes into the socket. The hub of the syringe nestled in the socket is thus clamped between the ball and a confronting wall of the socket to permit one to twist the hub off the syringe.

Other objects and advantages of the instant invention will become apparent from the following specification and figures of the drawing, in which,

Fig. 1 is a perspective view of a wrench incorporating the improvements of the instant invention;

Fig. 2 is a perspective view on a reduced scale and illustrates the relative positions of the wrench and hypodermic syringe in preparation of wrench engagement of the syringe;

Fig. 3 is a fragmentary perspective view and includes a sectional cutaway to show the details of the wrench socket;

Fig. 4 is a transverse view illustrating the syringe nestled in the wrench socket;

Fig. 5 is a fragmentary perspective view similar to Fig. 3, but showing a wrench socket without a bottom wall and thus representing a modified embodiment; and

Fig. 6 is a sectional cutaway top view of a wrench socket similar to the one shown in Fig. 5 but incorporating spring means.

Referring now to the figures, a wrench 10 is made of a sturdy body of metal or plastic material, and is preferably cast or molded as an integral unit. The wrench 10 is provided with even or smooth faces; a top face 28, a front face 29, a back face 30, and an under face 31. The contours of top and under faces 28, 31 are shaped so 3 that when looking downwardly upon wrench it appears elliptical, that is, gradually curved in shape, with the greatest width at the center. Oppositely extending arms and 16 gradually narrow toward respective ends 23 and 23'. The arms 15, 16 providethe leverage and serve as handles for grasping the wrench 10 when it is to be turned. Ends 23, 23" are rounded toatford comfortable handling.

I A recessed hub-engaging socket 11 is provided intermediate the arms 15, 16, and is formed by vertical and preferably fiat jaw surfaces 19, 20, 21 and 22 extending from top face 28 to a bottom wall 13 of the socket recess. Adjacent pairs of the jaw surfaces, 19 through 22, he along intersecting planes. of Fig. 1, the plane of each of the surfaces 19 through 22 forms a right angle with either of the adjacent surfaces, and thus provides a four-sided socket, but it would be keeping within the principle of the invention to use other forms of polygonal sockets.

The bottom wall 13 is provided with a beveled opening 14 and a slot 12 that communicates with opening 14 and extends through the front wall formed by the surfaces 21 and 29. The slot 12 is located, in the preferred embodiment, midway between the surfaces 20 and 22, and to this extent is centered with respect to the socket 11. The slot 12 is wide enough to pass the largest-diameter syringe needle expected to be used with any hypodermic syringe for which the wrench 10 is designed.

In the disclosed embodiment, the socket 11 is orientated with respect to a longitudinal axis 34 so that the front and back surfaces 21, 19 are in parallel relationship with respect to the axis 34, but the socket could be oriented so that the surfaces are angularly displaced with respect to the axis 34 without departing from the invention.

The hub 24 of a syringe 35 is usually provided with a rounded and small-diameter outer end such as 33. The wider, inner end of the hub is provided with at least two opposite fiat surfaces such as 37. Some hubs are provided with four flat surfaces at the wider end. To provide a rectangular shape for the socket 11 so that it can accommodate hubs that are rectangular in cross section, the length of each of the jaw surfaces 19 and 21 is greater than the length of each of the surfaces 20 and 22.

Since the jaws of the socket 11 are designed to engage the flat surfaces 37 of hub 24, the socket 11 must be deep enough to receive the outer end 33 of the hub 24 and at least a portion of each of the flat surfaces 37. If the socket 11 is too shallow, the flat surfaces 37 would project out from the socket 11, and wrench engagement would not be possible. Hence the wrench 10 is provided with its greatest vertical dimension, i. e., the distance between the top and under faces 28, 31, in the region of the socket 11. For convenience, the socket 11 is located midway between the ends of the arms 15, 16, and is made sufliciently deep by the truncated, triangular shape of the front and rear surfaces 29 and 30, as seen in Figures 1, 2 and 3.

The jaws of the wrench 10 are designed to withstand large forces. Accordingly, the thickness of the wall between the front face 29 and the surface 21 and the thickness of the wall between the back face 30 and the surface 19 are suflicient to withstand forces that are to be applied thereto during wrench use. To ensure adequate wall thickness, the wrench 10 is greater in width in the region of the socket 11 than in the region adjacent the ends 23, 23. The accommodate this structural requirement, the contours of the faces 28, 31 are gradually curved to form the elliptical-shaped body noted hereinbefore.

The embodiment of Fig. 1 may be modified by the elimination of the bottom wall 13, as illustrated in a socket 11' in Fig. 5. This change would require the doctor or nurse to hold the syringe 35 relative to the wrench 10 so that the flat surfaces 37 of the hub 24 are within the socket 11 during use of the wrench.

In the illustrated embodiment The syringe 35 includes a needle 25 fastened thereto by the hub 24, which in turn is fastened to a fluid-carrying barrel 26 by means ofa press-fit tapered surface 36. It should be noted that the wrench 10 is also usable for syringes employing a threaded connection instead of a press-fit tapered surface to join its hub to its barrel.

After using the syringe 35, the doctor or nurse removesthe hub 24 (needle 25 is still mounted thereto) and replaces these parts with a sterilized hub 24 and attached needle 25. Needle 25 is not removed from hub 24, but remains fixed thereto, and both are placed into the sterilizer after use.

In use, the wrench 10 is held so that the slot 12 is alongside and parallel to the needle 25, as illustrated in Fig. 2. Syringe 35 and the wrench 10 are then moved relatively to one another (see the arrowheaded dot-and-dash line in Fig. 2 that indicates this path of relative movement) so that the needle 25 passes through the vertical and horizontal portions of the slot 12 and into the opening 14 in the bottom wall 13. The pointed end of needle 25 is maintained beyond the under surface 31 at all times. Thus the point of needle 25 cannot strike any part of the wrench 10, and damage to the point is thereby avoided.

After needle 25 is lined up with the opening 14, hub 24 is moved into the socket 11 until its outer end rests against the bevel of the opening 14, as illustrated in Fig. 4. The flat faces 37 of hub 24 are now engaged by the jaws of the socket 11, and the wrench 10 is ready to be turned about the axis of barrel 26 to effect separation of hub 24.

Since the sockets 11 or 11 are usually made only slightly larger than the dimensions of hub 24 of the syringe for which the wrench is to be used, syringes of various sizes will require correspondingly sized sockets, which may be provided by a set of wrenches of graduated-size sockets. However, by providing a spring-pressed means in one wall of a wrench socket, a single wrench may be used for syringes of various sizes. In one embodiment of a spring-pressed means which is illustrated in a socket 11" in Fig. 6, a spring 18 is mounted in a drilled hole 40 in the wall between the rear face 30 and the jaw face 19. The axis of the hole 40 is parallel to an axis 32 (see Fig. 1). The face 30 is peened at the opening of the hole 40 to keep the spring 18 in place. The hole 40 does not extend through to the surface 19, but terminates at a shoulder formed by a coaxial, smaller hole 41 drilled through the jaw face 19, the shoulder acting as an abutment for the inner end of the spring 18. The drilled hole 41 provides a recess to receive a ball 17, which is secured to an axially extending inner end 42 of the spring 18 so as to normally lie partly in the hole 41 and partly in the socket 11".

Whenever a syringe hub is inserted in the socket 11, the ball 17 will be cammed into the hole 41 a distance which depends on the size of the hub, and the spring 18 will be correspondingly compressed. Thus, hub 24 will be clamped between the ball 17 and the opposite jaw face 21 of the socket 11", andhubs of various sizes may be firmly clamped by the action of the spring 18.

It will be understood that the spring 18 and the ball 17 may be replaced by equivalent but different spring structures to provide the sameservices. It is not necessary that the spring-pressed ball 17 be mounted in the wall opposite the'slot 12; However, it is preferable that it be mounted in one of the jaw-forming walls other than the wall containing the slot 12. Furthermore, it would be preferable when the spring-pressed ball 17 is used to eliminate the bottom wall 13 so that the clamped hub 24 may be withdrawn through the lower face 31 after the hub has been disconnected from the barrel 26.

It is intended that the foregoing embodiments be treated as illustrative examples of my invention and not in any limited sense.

What is claimed is:

A wrench for disengaging a needle-carrying hub of a hypodermic syringe comprising, a longitudinal body having upper, lower and side faces and oppositely extending arms, said arms providing gripping means for rotating said wrench, said upper face having a socket-forming recess intermediate said arms to provide jaw faces extending inwardly from said top face, adjacent ones of said jaw faces lying in planes intersecting at right angles, a bottom Wall terminating said socket-forming recess, one of said side faces having a vertical slot extending between said upper and lower faces of said body and communicating with said socket, said bottom wall having a beveled opening and a through slot extending from said opening in alignment with and communicating with said vertical slot, whereby a syringe-supported needle may be passed through said slots and aligned with said beveled opening 15 5 such needle-carrying hub.

References Cited in the file of this patent UNITED STATES PATENTS 611,564 Crump Sept. 27, 1898 2,691,912 Jones Oct. 19, 1954 FOREIGN PATENTS 400,755 Germany Aug. 21, 1924 14,103 Great Britain July 3, 1908 

